This invention relates generally to filters and more particularly concerns a compact and inexpensive filter for removing solid particles from a flow of liquid chemicals such as fertilizers, and for promoting mixing of dry materials with a liquid carrier.
The use of chemicals in agriculture is so important in modern farming as to be an indispensable part of the farm environment. Many of these chemicals, whether insecticides, herbicides, fertilizers, or other materials, are offered in liquid form. In preparing them for use, they must be transferred between tanks, mixed, and otherwise handled.
In many such liquid chemical handling operations it is important to separate the liquid chemicals from any foreign particles such as dirt, rust, pebbles, or the like. Removal of these solid particles protects expensive mechanical equipment, prevents equipment clogging, and in some cases may make the difference between success and failure in achieving a desired result with the liquid.
To remove these solid particles, filters are widely used. Many such filters, however, present almost as much difficulty to the filter user as do the solid particles themselves. Many filters or strainers are arranged to direct a flow of liquid in a direction oriented perpendicularly to a filtering screen. After a period of use, the filtering screen becomes partially closed from the collection of foreign particles. When clogging has increased and the flow of liquid through the filter screen has correspondingly decreased to unacceptable levels, the fluid flow must be halted, the filter housing opened, the screen removed, cleaned and replaced, and the housing then reassembled. Since many such housings require gaskets, it can be a difficult task to replace the gasket and reassemble the filter housing without damaging either the screen or the gasket. In some cases, the gasket itself must be discarded and a new gasket installed, thereby increasing the labor time and material cost.
In other filters, rapid flow of fluid at even a moderate pressure may cause collapse of the filtering screen and its disassociation from screen-holding parts in the filter housing. Under these conditions, unfiltered fluid can pass through the filter device, and the unwanted solid particles are not caught.
In other situations, dry, friable chemicals are dissolved or suspended in water to some other liquid carrier to form a desired treatment liquid. Under some circumstances, this mixing action is somewhat incomplete, and the tank contains a liquid and small clumps or nuggets of undissolved or unsuspended matter. Many previously offered filters will trap such clumps or nuggets but will not promote their breakup and dissolution in the liquid, because liquid in these filters is not flowing rapidly, or at least is not flowing in such a way as to encourage particle breakup and dissolution. When the filter is cleaned, these particles are removed and are wasted.
It is accordingly the general object of the present invention to provide an inexpensive, nonclogging, rugged and reliable filter mechanism for removing solid particles from a flow of liquid such as an agricultural chemical, and for encouraging the dissolution of unmixed, friable particles in a liquid carrier.
More specifically, it is an object of the present invention to provide a filter for such uses which provides a self-cleaning action to the filter member screen.
Another object is to provide such a filter which does not restrict the flow of fluid through the filter device.
A correlated object is to provide such a filter which requires only relatively low internal pressures within the filter mechanism.
A further object is to provide such a filter in a form having a filtering screen which is assembled within the filter so as to inhibit screen collapse and subsequent loss of filtering action.
Yet another object is to provide a filter mechanism of the type described from which the filtered solid particles can be easily removed without disassembling the filter housing. A related object is to provide such a filter in which the solid particles can be removed without damaging or even disturbing the gasket member carried between major housing parts.
Yet another object is to provide a filter of the type described in a small and compact housing.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings.
Throughout the drawings, like reference numerals refer to like parts.